Evolving models of warfarin management: Anticoagulation clinics, patient self-monitoring, and patient self-management

Since the introduction of dicoumarol in the early 1940s, oral anticoagulants have been the mainstay of therapy for the long-term treatment and prevention of thromboembolism. Anticoagulants have recently undergone a surge in popularity with the confirmation of their importance in preventing cerebral thromboembolism from atrial fibrillation 1-6 and now the confirmation of their beneficial effect in preventing recurrent myocardial infarction. 7-s In 1994 warfarin sodium was the fifth most prescribed cardiovascular medication and the thirteenth most prescribed medication in the United States. 9 Unfortunately oral anticoagulants have an extremely narrow therapeutic index, and many physicians are reluctant to treat patients because of the fear of hemorrhagic complications. 1°-13 Additionally, the l imitations of prothrombin time measurement 14 and the requirements of frequent monitoring, patient contact, and dose adjus tment make managing anticoagulation labor intensive and costly and provide another barrier to treatment. The complexity and fragmentation of routine care further enhance the potential for communication errors and laboratory testing that can lead to substantial complications and cost. In fact, the model of warfarin management is a potential risk fac~ tor for adverse events that is rarely considered when discussing wa~arin-related risk factors. The following discussion focuses on evolving models of anticoagulation management with the potential for improving the safety, efficacy, and cost-effectiveness of therapy and removing potential barriers to treatment. Coordinated anticoagulation care: The anticoagulation clinic. What constitutes coordinated anticoagu-